Electrical method and apparatus



y 1929- R. N. CONWELL 1,711,776

ELECTRICAL METHOD AND APPARATUS Filed Aug. 21, 1922 3 Sheets-Sheet l M 1929- i R. N. CONWELL 1,711,776 ELECTRICAL METHOD AND. APPARATUS Filed Aug '21. 1922 s Sheets-Sheet 2 Fig 4.

OW 0W I I I, I 6e FX! 5 Tl y 1929. R. N. 'CONWELL 1,711,776

ELECTRICAL METHOD AND APPARATUS Filed Aug. 21, 1922 s Sheets-Sheet 5 Patented May 7, 1929.

UNITED STATES PATENT OFFICE.

ROLLIN N. CONWELL, OF B LOOMFIELD, NEW JERSEY.

. ELECTRICAL METHOD AND APPARATUS.

Application filed. August 21, 1922. Serial No. 583,223.

1,508,361, 1,508.362 and 1,508,363, all dated a September 9, 1924.

Among the several objects of the invention may be noted the provision of inexpensive and durable electrical apparatus for effecting the various results hereinafter indicated, utilizing inductive action; and the provision of simple and reliable methods of attaining such results. Other objects will be in part obvious and in part pointed out hereinafter. This invention differs from the inventions set forth in the patents above mentioned, among other things, by the fact that means is provided for causing operation of the relay on a ratio differential basis. For example, with a. 2 setting, the relay will operate when the current in one winding exceeds the current in the other winding by 2% The relay is preferably provided with a plurality of ratio or percentage taps, so that the user can select the percentage at which he wishes the relay to operate.

The invention accordingly comprises the features of construction, steps and sequence of steps, combinations of elements and arrangements of parts, which are exemplified in the description hereinafter in connection with the accompanying drawings, and the scope ofthe application of which will beindicated in the following claims.

In the accompanying drawings, in which are illustrated diagrammatically several of various possible embodiments of the invention,

Fig. 1 is an elevation of one form of appa- "atus, showing normal conditions;

Fig. 2 is a plan of the parts shown in Fig. 1, excluding the connections;

Fig. 3 is a view similar to Fig. 1, showing circuit conditions upon reversal of current at one source;

Fig. 4 is a view similar to Fig. 1, showing circuit conditions when the currents at the sources are of unequal magnitude but not relatively reversed;

F ig. 5 is an elevation of a modified form of apparatus, showing normal circuit conditions;

Fig. 6 is a View similar to Fig. 5, showing circuit conditions upon reversal of current at one source; a

Fig. 7 is a view similar to Fig. 5, showing circuit conditions when the currents at the sources are of unequal magnitude but not relatively reversed; and

Fig. 8 illustrates switch gear utilizing the constructions shown in Figs. -1 to 7.

Similar reference characters indicate corresponding parts throughout the several views of the drawings.

Referring now more particularly to Fig. 1, there are illustrated at SM, S8 and S9 three terminals adapted to be connected to two sources of alternating current, which may be derived from one or more circuits; transformers T1, T5 adapted to be energized from said sources as hereinafter described; a primary winding X1, XG-X7 for each of the respective transformers; a leg or pole piece or core element L1, L5 for each of said respective transformers; and a secondary winding Y1, Y5 for each of said respective transformers.

The transformer fluxes are due to the magneto-motive' forces of the ampere turns of the primary and secondary windings of the respective transformers.

Another flux is induced bycurrent passing through two other windings 0W1, OTV5 connected to the respective secondary windings Y1, Y5 of the transformers. These two other windings are each wound upon two legs 0L2, 0L4. The net flux, if other than zero, cooperates with the transformer fluxes. These several fluxes induce electric currents in one or more conductors, for some useful purpose. In the present embodiments of the invention the conductor is a movable element, to wit, 9

a disc G pivoted as at 10 to one side of the plane of the laminated core (1 Thedisc is driven by the vectorial sum of the forces acting upon it, that is, the resultant force arising from the reaction of the resultant flux and the flux caused by the electric currents induced thereby in the driven element G. The driven element G may simply allow an observer to determine its position and/or direction of movement, as in synchronizers. Or the driven element may deliver mechanical power for power purposes, orrun a totalizer or operate a pointer or recording device (stylus or the like) or contacts MN or the like.

Ill)

In the present instance the apparatus is illustrated as a relay, and the disc G normally tends to rotate in one direction. Upon a reversal of current at one source, the disc tends to rotate in the other direction, re tarded if desired by one or more drag magnets DM (Fig. 2) and the torque developed is determined byfilie magnitude of the abnormality that causes the torque. Such torque may be used for any of the several purposes above named, for which such torque may be suitable.

N ormal oomlition.In tracing the several currents and fluxes during normal condition, assume one source of power to be connected across the terminals SM, S8 and the other to be connected across the terminals SM, S9,

with the currents from two sources equal and in phase, and the connections such that the currents from the two sources circulate. A connection of this type is illustrated in Fig. 8 hereinafter described. Assume the ampere turns in the two primary sections X6, X7 equal (connection 20). No current flows through primary X1 because its two terminals are connected to equipotential points.

There is thus no current in secondary Y1, and

none in other winding 0W1. Current in primary sections X6X7 induces in secondary Y5 a current that energizes the other winding OVVF). It will be seen by tracing the circuits, that a traveling field is formed, tending to move the disc in one direction.

Fig. 3.

Abnormal condition I, caused by reversal of current at one souroe.-Upon a reversal of current at onesource such as SMS8, the currents from the two sources do not circulate but oppose one another. Primary X1 is thus energized, inducing current in secondary Y1, which in turn energizes the other winding OlVl. The current in the latter winding produces polarities at the other legs 0L2, 0L4 opposite to the polarities produced at said legs by current in the other winding OVV5 (normal condition). The primary sections X6-X7 oppose and ordinarily neutralize one another, so that there is no current in sec ondary Y5 and none in the other winding OlVi"). The primary X1 is so wound with respect to the primary sections X6X7 that upon reversal of current at one source the traveling field produced by the several fluxes moves in the opposite direction to its direction during normal condition, thereby tending to rotate the disc in the direction opposite to the direction in which it tends to rotate during normal condition.

Fig. 4.

Abnormal condition I], caused by relative increase of current at one sou-roe without rewrsal. /Vhen the current at one source such as S9 increases relatively to the current at the other source, the currents at the two sources continue to circulate but their common terminal SM has a potential that is not midway between the potentials of terminals S8 and S9. Primary X1 is thus energized, inducing current in secondary Y1, which in turn energizes other winding 0W1. Current in primary sections X6X7 induces in secondary Y5 a current that energizes other winding OlV5. Primary X1 has preferably a much larger number of ampere-turns than primary X6 X7. The current in winding OlVl is therefore of greater magnitude than the current in the other winding OVV5, and hence the net flux at the other legs 0L2, 0L4 is of the same polarity as during abnormal condition I. It will be seen by tracing the circuits, that a traveling field is formed, tending to move the disc in the same direction as during abnormal condition I.

Similarly, an increase of current at S8 rela tive to S9 causes the disc to tend to rotate in the same direction as during abnormal condition 1'. For brevity, the circuit conditions are not here shown in detail.

Rsmn.The relay disc thus tends to move in one direction during normal condition. Upon a reversal of current at either source of power (abnormal condition I) the relay tends to move in the other direction. Upon an in crease of current at either source of power,

without reversal (abnormal condition II) the relay tends to move in the same direction as during abnormal condition I.

Fi s. .Z/; modified to 71am primaries X6 and X7 unequal.

Fig. 5.

Construction-The relay shown in Fig. 5 is constructed in similar manner to the relay in Figs. 1 to 4 except that the other windings OlVl, (V5 are replaced by another winding OW, and the secondary windings Y1, Y5 are connected to circulate during normal condition and to oppose upon a reversal oi current in either of said secondary windings.

, The other winding OlV is connected to normally equipotential points of the circuit that includes the secondary windings Y1, Y5.

Normal oomlifima--ln tracing the several currents and fluxes during normal condition. assume the sources to be connected as in Fig.

The current in primary sections X6X7 in duces in secondary Y5 a current that energizes other winding OW. It will be seen by tracing the circuits that a traveling field is formed, tending to move the disc in one direction.

Abnormal condition I, caused by reversal of current at one sou.roe.Upon a reversal of current at one source, such as SM, S8, the currents from the two sources do not circulate but oppose one another. Primary X1 is thus energized, inducing current in secondary Y1. The primary sections X6, X7

oppose and ordinarily neutralize one another so that there is no current induced in secondary Y5. The current in secondary Y1 energizes the other winding OW in a direction opposite to the direction during normal condition. The primary X1 is so Wound With respect to the primary sections X6-X7 that upon reversal of current at one source the traveling field produced by the several fluxes moves in the opposite direction to its direction during normal condition, thereby tending to rotate the disc in the direction opposite to the direction in which it tends to rotate during normal condition.

' Fig. 7.

' reversal.WVhen the current at one source such as S9 increases relatively to the current at the-other source, the currents at the two sources continue to circulate but their common terminal SM has a potential that is not midway between the potentials of terminals S8 and S9. Primary X1 is thus energized, inducing current in secondary Y1. Current in primary sections X6X7 induces current in secondary Y5. The former current is of greater magnitude than the current induced in secondary Y5. The terminals of other winding 0W1 thus have the same polarities as during abnormal condition I. It will be seen by tracing the currents, that a traveling field is formed, tending to move the disc in the same direction as in abnormal condition I.

lisume.-The relay disc thus tends to move in one direction during normal condition; and in the other direction upon a reversal of current at either source of power (abnormal condition I) or upon a relative increase of current at one source of power without reversal (abnormal condition II).

Figs. 5 to 7 modified to have primaries X6 and X7 unequal.

(See connections 21 and 22 in Fig. 5). The construction and operation are similar to those above described, except that there is normally current in primary X1 and therefore induced current in secondary Y1. This alters the restraint due to current in primary section X6"X7.

- Fig. 8.

0onstmot'ion.ln Fig. 8 three relays of the type shown in Figs. 1 to 4 or Figs. 5 to 7 are shown, connected to operate as a directional current switch gear, with a three-phase grounded-neutral generator 0. On the neutral side of each armature winding is a current transformer CN, one side of which is connected to the left terminal of the corresponding relay andthe other to the right terminal of the relay. 011 the bus side of each transformer winding is a current transformer CL, one side of which is connected to the left terminal of the relay for that phase and the otherto the middle terminal of the same relay. The several windings are so connected that during normal operation the currents in each set of transformers CL, CN circulate, corresponding to the normal condition of the relay as described above; whereas upon a relative reversal of current in the transformers CL, CN of any phase (caused, for example, by a fault in the armature Winding of that phase) the relay for that phase operates as described above under abnormal condition I and trips the circuit-breaker CB. Relative increase of current in one current transformer with respect to the other current transformer of the same phase without re-- versal, causes action of the relay as indicated above in connection with abnormal condition II.

In general. I

If during normal condition the two sources 1 rents, the relay tends to rotate in the same,

direction as if the currents were 180 degrees apart.

The above also applies to embodiments of the invention in apparatus other than relays, that is, an acute-angle out-of-phase relation between the currents of the two sources does not cause the device to operate other than as described above under normal condition or abnormal conditioii II respectively; and during reversal, when the reversal is not exactly 180 degrees, the device nevertheless tends to operate in the same manner as when the currents are 180 degrees apart.

In the system shown in Fig. 8, the relays may each be provided with a movable and two fixed contacts, so that the relay closes one circuit during normal condition and another circuit during reversal. The illustrated system is merely representative of apparatus protection, and of various other classes of systems to which the present invention, in certain of its aspects, is applicable.

From the above it will be seen that the several objects of the invention are attained and other advantageous results achieved.

As many modifications of the embodiments above illustrated might be made without departing from the spirit or scope of the present invention, it is intended that the above description and accompanying drawings and claims shall be interpreted as illustrative and not in a limiting sense.

I claim:

1. In apparatus of the class described, in combination, a plurality of transformers, primary and secondary windings therefor, the primary windings adapted to be energized from a circuit including a plurality of sources of power, one primary being connected to said sources and to a point on the other primary, and the other primary being connected in said circuit, and means cooperating with said secondary windings for producing fluxes coacting with the transformer fluxes to set up traveling magnetic fields.

2. In apparatus of the class described, in

combination, a plurality of transformers, pri-.

mary and secondary windings therefor, the primary windings adapted to be energized from a circuit including a plurality of sources of power, connected to one another for circulation and opposition, one primary being connected to said sources and to a point on the other primary, and means cooperating with said secondary windings for producing fluxes coacting with the transformer fluxes to set up traveling magnetic fields.

3. In apparatus of the class described, in combination, a plurality of transformers, primary and secondary windings therefor, the primary windings adapted to be energized from a circuit including a plurality of sources of power, connected to one another for circulation and opposition, one primary being conncctedto said sources and to a point on the other primary, and the other primary being connected in said circuit, and means cooperating with said secondary windings for producing fluxes coacting with the transformer fluxes to set up traveling magnetic fields.

4:. In apparatus of the class described, in combination, a plurality of magnetically co acting transformers, primary and secondary windings therefor, the primary windings adapted to be energized from a circuit including a plurality of sources of power, connected for circulating currents during normal operation, one primary being connected to said sources and to an intermediate point on the other primary, and the other primary being connected in said circuit, and means cooperating with said secondary windings for producing fluxes coacting with the transformer fluxes to set upv traveling magnetic fields.

5. In apparatus of the class described, in combination, a plurality of transformers, primary and secondary windings therefor, a circuit adapted to be connected to two sources of power for circulating currents during normal condition, one of said primaries being connected to said sources and to an intermediate point on the other primary, the other primary being connected in said circuit, means cooperating with said secondary windings for producing fluxes with the resultant of the transformer fluxes, means for combining said transforn'ier fluxes and said other fluxes to produce traveling fields, and a member responsive to said traveling fields.

6. In apparatus of the class described, in combination, a plurality of transformers, primary and secondary windings therefor, the primary windings adapted to be energized from a circuit including a plurality of sources of power, one primary being connected to said sources and to a midpoint on the other primary, and the other primary being connected in said circuit, and means cooperating with said secondary windings for producing fluxes coacting with the transformer fluxes to set up traveling magnetic fields.

7. In apparatus of the class described, in combination, a plurality of transformers, primary and secondary windings therefor, the primary windings adapted to be energized from a circuit including a plurality of sources of power, one primary being connected to said sources and to a non-mid-point on the other primary, and the other primary being connected in said circuit, and means cooperating with said secondary windings for producing fluxes coacting with the transformer fluxes to set up traveling magnetic fields.

8. A directional current switch gear comprising a plurality of sources of current connected in a circuit for circulation during normal operation and for opposition upon relative reversal of current in said sources, a relay having a winding in said circuit and a winding connected to said sources and to an intermediate point on the first winding, and means whereby said windings cause traveling tields tending to cause movement of the relay in one direction during circulation and in another direction during opposition of the currents in said sources.

9. In apparatus of the class described, in

combination, a plurality of transformers, primary and secondary windings therefor, a cir-.

cuit adapted to be connected to two sources of power for circulating currents during normal condition, one of said primaries being connected to said sources and to an intermediate point on the other primary, the other primary being connected in said circuit, opposing windings connectedwith the respective secondary windings for producing fluxes with the resultant of the't-ransformcr fluxes, means for combining said transformer fluxes and said other. fluxes to produce traveling fields, and a member responsive to said traveling fields.

10. In apparatus of the class described, in combination, a plurality of transformers, primary and secondary windings therefor, a circuit adapted to be connected to two sources of power, one of said primaries being connected to said sources and to an intermediate point on the other primary, the other primary being connected in said circuit, the secondaries being connected in a circuit, and a winding connected. across said circuit and adapted to produce fluxes with the resultant of the transformer fluxes, and means for combining said transformer fluxes and said other fluxes to produce traveling fields.

11. In apparatus of the class described, in combination, a plurality of transformers, primary and secondary windings therefor, a circuit adapted to be connected to two sources of ower for circulating currents during norma l condition, one of said primaries being connected to said sources and to an intermediate point on the other primary, the other primary being connected in said circuit, the secondaries being connected in a circuit, and a winding connected across said circuit and adapted to produce fluxes with the resultant of the transformer fluxes, means for combining said transformer fluxes and said other fluxes to produce traveling fields, and a member responsive to said traveling fields.

12, The method of inducing currents in a conductor, which comprises producing magnetically coacting fluxes from a plurality of sources of power connected normally for circulation but for opposition upon relative reversal of current in said sources, producing from the said fluxes fluxes in quadrature with the first fluxes, and. causing said several fluxes to combine to form one or more travcling fields inducing currents in said conductor.

13. In apparatus of the class described, in combination, a plurality of transformers, primary and secondary windings therefor, the primary windings adapted to be energized from a circuit including a plurality of sources of power, one primary being connected to said sources and to a point rn the other primary, the latter connection being movable and the other primary being connected to said circuit and means cooperating with said secondary windings for producing fluxes coacting with the transformer fluxes to set up traveling magnetic fields.

In testimony whereof, I have signed my name to this specification this fourteenth day of August, 1922.

ROLLIN N; CONWELL. 

